1. Field of the Invention
The present invention is generally related to a method for operating a propulsion system of a watercraft and, more particularly, to a technique for controlling the relationship between the connecting and disconnecting of an energy recharging system for the watercraft and how that system interrelates with the control of various components on the watercraft that allow it to move in response to changes in the condition of its transmission and changes in the operating status of its engine.
2. Description of the Related Art
The basic problem toward which the preferred embodiments of the present invention are directed is the avoidance of accidents that can occur if a watercraft is moved relative to a dock while it is physically connected to a recharging system. At a minimum, some connective device can be severely damaged. Since the recharging of the energy storage components (e.g. flywheel, fuel tanks, capacitors, rechargeable batteries) requires some physical interconnection between an onshore energy source and a mechanism on a watercraft and, in turn, between the mechanism and the energy storage device on the watercraft requires a physical connection that is relatively sturdy, movement away from the dock or marina will tear or destroy the energy transfer connection device or the components to which it was attached. The basic cause of this damage can be identified very simply. It is the simultaneous occurrence of two situations. One situation is the movement or potentially imminent movement of the marine vessel. The other situation is the recharging operation or imminent beginning of a recharging operation or the continued attachment of an energy transfer device after the completion of a recharging operation. Stated even more simply, if the watercraft is connected to some stationary device on shore and the marine vessel is able to move relative to the dock, very serious problems can occur and significant damage is likely to result. Most systems developed to date have relied on some type of switch which represents the position of a component, such as a door covering an electric socket on a car. Some of the known devices which address this issue are described below.
U.S. Pat. No. 3,898,547, which issued to Poole on Aug. 5, 1975, describes an electric vehicle charger shutoff interlock system. It prevents a vehicle from being driven while the batteries are being charged and prevents activation of the charger until the direct current connection of the battery charger to the electric vehicle is completed. This is accomplished by using standard, low cost readily available solenoid relay switches and a three point connector and plug assembly. Two of the points of the connector and plug assembly provide direct current connection to the batteries of the electric vehicle. The third contact completes a series circuit through two relays one of which is located on the electric vehicle to prevent operation of the vehicle when activated, and the other relay which is connected to permit energization of the battery charger when activated.
U.S. Pat. No. 5,206,578, which issued to Nor on Apr. 27, 1993, describes a monitoring system for batteries during charge and discharge. The batteries are monitored while they are being charged or discharged, where the batteries comprise a series of modules or cells that are connected in series. A terminal is placed between each adjacent pair of modules and at each end of the battery, so that voltage across each module may be measured at the pair of terminals that define the module.
U.S. Pat. No. 5,220,268, which issued to Rose et al. on Jun. 15, 1993, describes a battery charging system and connection apparatus therefore. Connectors are adapted for mating in electrical contact. A bracket is provided for mounting the first connector to the vehicle. The second connector is mounted on the digital end of cables leading from the battery charger. The apparatus also includes a switch for interrupting the electrical circuit between the battery and the drive motor prior to mating of the first and second connectors. The invention also relates to a battery charging system incorporating a battery charger, a charger receptacle mounted on the vehicle and a plug for operatively connecting the battery charger to the charger receptacle.
U.S. Pat. No. 5,344,330, which issued to Hoffman on Sep. 6, 1994, describes an electrical connector assembly, especially for an electric vehicle. The electrical connector assembly includes a male connector or plug with electrical contacts and a female electrical connector or receptacle with mating electrical contacts. Both the receptacle and the plug have a cover for selectively covering and uncovering its electrical contacts to prevent inadvertent contact with the electrical contacts and to protect the electrical contacts from the environment. In the preferred embodiment, the covers of the plug and receptacle are automatically uncovered and the receptacle contacts are moved transversely to the plug insertion direction and into contact with the plug female contacts only after full insertion of the plug into the receptacle. The plug can be inserted into the receptacle with little or no force by the user since the contacts of the plug and receptacle are not electrically coupled together until after full insertion of the plug into the receptacle.
Japanese patent application 05-278871, which was filed on Oct. 13, 1993, describes an interlock apparatus of a vehicle carried charger. A vehicle carried charger charges a vehicle carried battery by connecting a charging cable in external power supply to a charging plug receptacle of a charger accommodated in a charging box providing a cover which can be opened or closed freely. An interlock switch for detecting opening or closing condition of the cover is provided near the cover and this interlock switch is connected to a key switch circuit. Thereby, when the cover is closed the interlock is released.
Japanese patent application 05-181796, which was filed on Jul. 23, 1993, describes a control device for an electric vehicle. It makes a connector connection detecting signal from a detection switch for a charging connector valid when a vehicle velocity signal is in a vehicle stop state, it turns off a relay by a relay control signal, and it cuts off electrification of a motor.
Japanese patent application 07-333934, which was filed on Nov. 28, 1995, describes a power supply unit for an electric car. A switch movable contact of a charging terminal cover switch comes to one position when the charging terminal block of a connector is closed and comes to another position when the charging terminal cover is open.
Japanese patent application 08-140450, which was filed on Jun. 3, 1996, describes an electric motor car. The car is equipped with a casing for charge connection which has a built-in connector where the output terminal of a charger to charge a storage battery for driving itself is to be connected and which is selectively covered by a charge lid, the casing for connector is opened to enable it to charge by exciting a charge lid solenoid when a charge lid open request is made by a charge lid open request switch and besides the mobile contact of a shift position detection switch is in contact with the parking position contact.
U.S. Pat. No. 5,757,595, which issued to Ozawa et al. on May 26, 1998, describes an apparatus for displaying battery charging of an electric vehicle. An apparatus for displaying the charging of the battery of an electric vehicle has a charging connector mounted on an outer panel of a vehicle body of the electric vehicle, a lid openly mounted on the panel in covering relation to the charging connector and a cavity defined in the outer panel, and a display panel disposed in the cavity for displaying a period of time required until the battery is fully charged and/or a charged capacity of the battery is exceeded. The driver of the electric vehicle can easily recognize the remaining time required until the battery is fully charged and a percentage of the fully charged capacity of the battery to which the battery is presently charged, from outside of the electric vehicle.
U.S. Pat. No. 5,921,799, which issued to Forrester on Jul. 13, 1999, describes an electrical receptacle with releasable locking mechanism. A body formed from upper and lower body portions encloses line and neutral contact assemblies and a ground contact assembly. The line and neutral contact assemblies carry a latching mechanism which releasably and automatically engages the holes in the line and neutral prongs of a standard electrical plug. A collar, carried by the body slides between a forward position and a rearward position. The collar is biased to the forward position.
U.S. Pat. No. 5,937,781, which issued to Isella et al. on Aug. 17, 1999, describes as floating piling attachment device with shock absorbing capability. A watercraft mooring device is described which permits the watercraft to rise and drop vertically with the water level and which provides both direct shock absorption between the watercraft and the fixed mooring point, such as the pier or piling, and protection against scraping between the watercraft and the fixed mooring point. A floating tube is provided, which is designed to loosely fit over and around the fixed mooring point and which provides one or more attachment grooves for holding an attachment rope, cord or cable in place.
U.S. Pat. No. 5,965,997, which issued to Alwardi et al. on Oct. 12, 1999, describes a battery monitoring circuit with storage of charge and discharge accumulation values accessible therefrom. The monitor circuit is operable to be connected to an external CPU or similar system through a single wire communication port for transferring information back and forth. There is also provided an external signal on a line for indicating charge or discharge activity in the monitoring circuit. The monitor circuit is operable to collect information regarding the amount of charge input to the battery and the length of time that the charge is input to the battery and also the amount of charge that is removed from the battery and the length of time that the charge is removed.
U.S. Pat. No. 6,057,667, which issued to Mills on May 2, 2000, describes a booster with switch actuated cable decoupler. It is provided for applying electrical power to a device in which a power source having positive and negative terminals is disposed in a housing, with electrical cables extending from their respective positive and negative or grounded terminals to exterior of the housing, with an electrical switch interposed in one of the electrical cables interior of the housing manually actuable from outside of the housing, with an electrical circuit operatively coupled to one of the cables and the electrical switch, whereby the electrical circuit effects automatic closing of an electrical switch upon imposition of a predetermined minimum voltage to the cables, and effects opening of the electrical switch upon the second cable having a voltage less than the predetermined minimum voltage, and with a voltage comparator and its associated circuitry to indicate a level of charge for the power source.
U.S. Pat. No. 6,203,355, which issued to Neblett et al. on Mar. 20, 2001, described a universal charge port connector for electric vehicles. A connector assembly has a male and female connector. The male connector has a housing with electrical contacts to conduct AC or DC current. The female connector also includes a housing to couple with the male housing. The female housing includes electrical contacts to electrically couple with male electrical contacts. A latch mechanism is associated with the male or female connector housing to releasably couple the male and female connectors together.
U.S. Pat. No. 6,652,330, which issued to Wasilewski on Nov. 25, 2003, discloses a storage battery monitoring system with automatic electrical load shedding. A method for controlling the electrical system of a marine vessel comprises the steps of measuring a battery potential, comparing the battery potential to a threshold voltage magnitude, and then disconnecting one or more of a plurality of electrical power consuming devices when the voltage potential is less than the threshold voltage magnitude. This is done to avoid the deleterious condition wherein an engine of the marine vessel is operating at idle speed and attempting to charge the battery while a plurality of electrical power consuming devices are operating and drawing sufficient current from the alternator to prevent the proper charging of the battery. In these circumstances, the battery potential can actually be depleted as the battery attempts to provide the additional required electrical current for the loads.
U.S. Pat. No. 6,802,749, which issued to Justus on Oct. 12, 2004, is describes a marine vessel trolling and battery recharging system. It includes an electric generator/trolling device having a propeller. The device is electrically coupled to a battery and extendable downwardly from the marine vessel into the water. When electrical power is supplied to the generator/trolling device in a first orientation, the propeller turns and serves as a trolling motor. However, when the generator/trolling device is positioned in a second orientation and the main engine of the marine vessel is powered, the propeller spins freely and serves to recharge the battery of the marine vessel.
U.S. Pat. No. 6,834,688, which issued to Ono et al. on Dec. 28, 2004, describes a fuel gas filling system for a vehicle having a supply section and a fuel lid, which includes an opening operation section to which an opening operation for the fuel lid is applied, an operation wire, which is provided between the opening operation section and the fuel lid, for making the fuel lid respond to the opening operation applied to the opening operation section, and a locking device having a movable element, a fixed element, a lock pin, and an actuator.
U.S. Pat. No. 6,905,362, which issued to Williams on Jun. 14, 2005, describes an electric vehicle battery rapid charging connector. It includes a connector plug that is attached to an electrical cable at one end that is, in turn, connected to a charging system at the remaining end of the cable. The connector plug is adapted to fit into a mating receptacle that is attached to the electric vehicle. A pair of cavities in the connector plug are adapted to receive any combination of modules that includes switches, lights, or blank filler plugs.
U.S. Pat. No. 6,964,821, which issued to Hirakata on Nov. 15, 2005, describes a fuel cell fuel supply system and a mobile body. An electric vehicle with fuel cells mounted thereon has a fuel tank that stores a fuel therein and a connector receptor that is connected to the fuel tank and is open to the surface of the vehicle body. A connector of a predetermined hydrogen supply device is fitted in and attached to the connector receptor so that a supply of fuel is fed from the hydrogen supply device to the electric vehicle.
U.S. Pat. No. 7,205,747, which issued to Wu on Apr. 17, 2007, describes a system and method for monitoring a charging period in a battery charger. It describes a method and apparatus for disabling a charging counter circuitry within a battery charger. The apparatus includes circuitry connected to a pin associated with the charging counter circuitry of the battery charger, the circuitry receiving a signal from a device connected to the battery charger. The circuitry disables the charging counter circuitry responsive to a signal from the device at a first level and enables the charging counter circuitry responsive to the signal from the device at a second level.
U.S. Pat. No. 7,218,118, which issued to Gonring on May 15, 2007, discloses a method for monitoring a condition of a battery. It provides the measuring of a voltage characteristic of the batter, comparing the voltage characteristic to a preselected threshold value, and a evaluating the condition of the battery as a function of the relative magnitudes of the voltage characteristic and the threshold value. The voltage characteristic of the battery is measured subsequent to a connection event when a connection relationship between the battery and an electrical load is changed. The electrical load is typically a starter motor which is connected in torque transmitting relation with an internal combustion engine. The voltage characteristic is preferably measured at its minimum value during the inrush current episode immediately prior to cranking the internal combustion engine shaft to start the engine.
U.S. Pat. No. 7,410,395, which issued to Kawai et al. on Aug. 12, 2008, describes a parent child type boat with a generator. The boat has an electrical power generating device, such as a fuel cell. The boat includes a parent boat and at least one child boat which is smaller than the parent boat. The parent is boat is equipped with a generating device. The child boat is equipped with a battery and an electric propulsion device. When the child boat is docked with the parent boat and electrically connected thereto, power can be supplied to at least one of the battery and the electric propulsion device of the child boat from the generating device of the parent boat.
U.S. patent application Ser. No. 12/230,675, which was filed on Sep. 3, 2008 by Kamaga, describes an electric powered vehicle chargeable by external power supply. An open/closed detection unit detects whether a lid covering a charge connector is closed or opened and outputs the results of the detection to a vehicle control unit. A connection detection unit receives a first signal and detects whether a plug and the charge connector are connected or not based on the voltage of the first signal. The vehicle control unit determines, based on the result of the detection by the connection detection unit and information about an external power supply indicated by a second signal, whether the first signal is normal. When the first signal is abnormal, the vehicle control unit determines based on the result of detection by the open/close detection unit, whether the lid is closed. When the lid is closed, the vehicle control unit controls the vehicle state to be in the travel-enabled state.
The patents described above are hereby expressly incorporated by reference in the description of the present invention.
Those skilled in the art of marine vessel design are aware of the many functional and structural differences between a watercraft and an automobile or land-based vehicle. One example of these differences is the fact that it is rather easy to construct a recess in the outer surface of an automobile and provide a lid, or door, which makes closure available over the recess where a cable would normally be inserted to connect the automobile to a source of energy, such as electrical power or hydrogen gas. Marine vessels are quite different in that most external surfaces of a boat become significantly wetted or submerged during normal use of the boat. In addition, the visible surfaces that do not become directly submerged or significantly wetted during normal use of the boat are subject to frequent exposure to splashing during normal use of the marine vessels, particularly pleasure craft. Although lids and covers can be provided with seals, maintaining the integrity of the seals over time can be quite difficult, particularly in view of the fact that the seals would be required to protect electrical contacts from contamination with the water in which the watercraft is operated. This water, located at or near the many miles of shoreline of the United States, is very likely to be seawater which is highly conductive and likely to subject the associated circuitry to potentially damaging contact and corrosion. Therefore, providing a switch associated with a lid or cover as described in many of the patents and publications described above is impractical when proposed in conjunction with hybrid marine vessels. This is particularly relevant in view of the severely high voltage magnitudes proposed for use in recently developed hybrid boats. Allowing seawater to migrate into a switch or female receptacle that is expected to then carry 300 volts DC can subject the marine vessel to potential damage.
Due to the limited amount of exposed surface area on a watercraft which is not subject to frequent and significant wetting, it is difficult to identify adequate locations for receptacles where a cable can be plugged into a location on the boat where the receptacle is not likely to be wetted, potentially with saltwater. If an appropriate location is found within the structure of the marine vessel where wetting is unlikely, it can present difficulties in locating the connector and it could require a relatively long cable to reach from that position within the structure of the watercraft and also reach a power source on shore.
It would therefore be significantly beneficial if a methodology could be developed which avoids the need for switches associated with lids that cover the electrical receptacle on the boat while also avoiding the potential simultaneous recharging of batteries while the boat moves relative to an energy source located on shore.